Drying apparatus.



PATBNTED DEG. si, 19o?.

G. W. MGMULLEN. DRYI G APPARATUS` y APPLICATION ILED MAY 26.19.05.

4 SHEETS-SHEET 3.

No. 875,368. PATENTED DEG. 31, 1907. G. W. MGMULLBN.

DRYING APPARATUS. APPLICATION FILED MAY26,1905.

4 SHEETS-SHEET 4..

' GEORGE W. MCMULLEN, OF PIGTON, ONTARIO, CANADA.

DRYING- APPARATUS.

Specification of Letters Patent.

Patented Dec. 31, 1907.

Application ned May 26, 1905. sain Nn. 262.381.

To all whomit may concern:

Be it known that I, GEORGE W. MOMUL- LEN, a resident of Picton, Prince Edward county, Ontario, Canada, have invented certainnew and useful Improvements in Drying Apparatus, of -which' the following is a speciiication.

This invention relates to improvements in drying apparatus, and refers more specifically to an apparatus partaking of the nature of a drying kiln.

Among the salient objects of the invention are to provide an apparatus whereby the water or other volatile constituents may be extracted from commodities under regulated and controlled conditions best suited for dry ing the specific substance or commodity in hand; to provide an apparatus whereby the desiccation may be effected in the presence of a moist and warm atmosphere, the degree of humidity of which is at all times under control and may be so regulated as to best secure the desired result; to provide an ap paratus whereby substantially equable temperatures and conditions may be maintained at similar levels throughout the desiccating chamber; to provide an extremely efficient arrangement and construction of vapor condensing apparatus; to provide :improvements in the construction .and arrangement of the apparatus whereby the moist and warm condition of the drying atmosphere is maintained and controlled; to provide a construction in the drying chamber which is most effective in insulating the interior against external temperature conditions; and in general to provide a simple, efficient and economically constructed apparatus of the character referred to.

To the above ends, the invention consists in the .matters hereinafter described and more particularly pointed out in the appended claims.

The invention will be readily understdbd from the following description, reference b einv had tothe accompanying drawings, inA

Wind-l1,-

Figure 1 is a`vertical cross-sectional view taken in the plane indicated by lin'e l1--1 of Fig. 3, and looking in the direction of the arrows; Fig. 2 is a similar view, taken in'a plane at right angles to that of Fig. 1, and upon the plane indicated by line 2 2 of f. lFig. 3; Fig-3 isahorizontal sectional view ,S51-,takenI ina *plane just above'the radlator's,

. and li'yolging downwardly, parts of the radlators and superposed liquid-receptacles being broken away to expose subjacent parts; Fig.`4 is a perspective view of one of the condenser elements; Fig. 5 is a fra mendistributing troughs; and Fig. 6 is a view sinular to that of Fig. showing a modified construction.

The apparatus herein shown is designed for that form of evaporating plant whrein the material to be acted upon is arranged in the,A u per ortion ofa vapor-tight or closed cham er wliich derives its heat from a source located below the same, and is provided at a still lower point with condensers. In` the practical carrying out of desiccating withA such an apparatus, the material placed in the drying chamber proper is subjected to the actionof the heat, w ereby its moisture 'is expelled, and this moisture-laden atmosphere 1s condensed as it descends and comes into contact with. the condensers in the lower part of the apparatus.

In many cases'it is necessary to supplement the moisture expelled from the commodity being dried with additional vapor, so

that the air may-at all times be in that condition best suited for effecting the desiccation without objectionably affecting the corn.- modity under treatment. This moist atmosphere has been found essential, not only in maintaining theporosityf of materials of the denser character, but also in drying those which contain larger percenta es of moisture, such as fruits, eggs, vegeta les, milk andl other food and analogous products, in which case its presence arrests germ development and action, and maintains the color, natural flavors and other desirable characterlstics of the materials.

tary perspective view of one of the iquidVv In practice, I have found that many matially closed and heated chamber, where the structure is provided with well insulated walls vso designed as to avoid t9 the utmost loss of heat by radiation, the tem erature at the top will nevertheless be sli ht y in excess of that in the lower portions; ut for certain thevhea'ting devices distributed throughoutl the drying-.chamber and arranged to locally heat the material. Forexample,.wherc milk, `tomatoes, apples and the like are being dried, it will not do tohaveall the pans andl 'racks arranged in series. about a single heating de'- vice, sinceithose nearer the source of heat lwill dry more quickly. than those more' remote, and the results will be un-uniform.

The present apparatus is designed to aord means for maintaining the necessary,con ditions referred to for securing the desired results'.v

Referring tothe drawings, 1 designates as a'whole an outer inclosure, the walls whereof are of. suitable heat-insulating material so as to confine the Aheat largely within the chamber formed by said closure and protect the latter against the influence of external tem eratures. The inclosure is convenient y provided at one side with a large door 2, through which the materials to be heated may be introduced and withdrawn. The walls of saidouter inclosure 'are desirably double, as indicated at 4 and 5, and spaced apart so as to provide an intervening insulating space 6, which surrounds the side walls and top of the-chamber. inclosure is arranged an inner incl'osure 3, the walls whereof are likewise spaced away from the outer walls so as to provide a surrounding Y insulating lspace 7. Said inner inclosure may conveniently terminate at`1ts lower edges coincldent with the workmgfloor or track rails of the kiln, since the material the side walls-, as indicated at 9.

being treated is always supported above that level. il 'n In order that there may be as little 'circulation ofvair'as practicable in thel'insulating space 7 intervening betweenthe outer and' inner inclosures, said space is shown as subdivided more or less g partition strips 8 being showrr as extending across the top ofthe kiln and also vertically at intervals apart around That part f the inner inclosure opposite the door 2, isv made separate from the remaining walls and supported by the door proper, said independent part being designated 3, and shown as supported upon the inner face of the door by means of a plurality of supporting and spacing studs 10. The door is shown as hinged at one edge, as indicated at 11.

cas the lower part of the kilriatA intervals apart, and upon these timbers aremounted track rails 413, which serve lto support a wheeled 'drying truck (not shownl in a well with each other.

i2 designates a series ofcross timbers ar ed in a horizontal plane and extendlng .of the respective condenser troughs.

understood manner. A short distance below the timbers 12 are arranged a plurality of radiator coils 14; these coils being desirably, and as shown hereinformed of flat loops or turns of pipe arranged inthe same horizontal plane and supported upon suitable cross strips 15 spaced at intervals apart, and in turn supported at their ends upon ledges 1G. A

17, 17 and 18 designate a plurality'of open trough-like receptacles arranged to extend transversely of, and resting upon the radiator coils these receptacles being spaced apart and vdesirably arranged to extend parallel A steam pipe 19 is arranged to communicate with each of the two outermost receptacles 17, and the receptacles 17 are arranged to communicate with each of the intermediate receptacles 18 by means oft circulating pipes 20. A main steam-supply pipe 21 communicates with the inlet end of the radiator coils, while a similar exhaust pipe 22 is connected with the discharge end of said coils; all of these several steam pipes referred to being arranged to enter 'through theside walls ofthe kiln, as shown clearly in the drawings.v

In the lower part of the kiln, and prefer.

ably arranged to rest upon a series of cross timbers 23, is a series of condensers 24, which may be of any suitable construction so far as the general scope of. the invention is 'concerned, but are of peculiar and novel con# struction, as shown in the present instance. Each condenser unit consists of a metal trough of relatively deep and narrow form, and desirably made of such length as to eX- tend across the principal width of the drying chamber. I conveniently construct these troughs 24 by bending up arectangular sheetmetal blank to form a deep, narrow U-shaped trough, and then compress the end margins 25 together and unite them by solder, so as to form a one-piece structure, as best seen in perspective view, Fig. 4. I preferably arrange these condenser troughs side by side parallel with each other,.and spaced apart by means of space blocks 26, each having a thickness approximately equal to or slightly greater than, the width of the trough,- the series being eX- tended entirely across the interior of the kiln from side to side, so that the side walls sup` 'of the troughs for the purpose of repair or cleansing without disarranging the 'rest of the series.

In order to supply the several troughs with cooling liquid, I arrange a transverse feeder trough 27, extending across rthe end of the series of troughs, and provided in its bottom with a series of outlet nozzles 28, one for each An inlet pipe 29 enters through the wall of the kiln 'In order to dispose of the overtloiv, a drain pipe communicates with the bottom of the kiln, which drain pipe may, if necessary, he provided with a'seal or trap 31.

in order to provide for a more ready de-.

scent ot' the heavy, moist atmosphere from the drying chamber, the heating coils or radiators and the condensers are made somewhat shorter than the transverse width of the chamber, as best seen in Figs. l and 3, thus leaving a more or less open space bet-Ween the ends of the coils and condeiiscrs and the opposite side Wall.

in order to prevent the establishment of a pronounced upward current in any one part of the drying chamber, I provide a series of baffle boards or plates, designated 32, which are interposed between the condensers and the radiatorv coils and so arranged that-the air Will filter upwardly. through the spaces between the entire series. This insures an even distribution of the rising Warm air and the longer retention of the charged air in the vicinity of the condensers, besides preventing the establishment of a distinct upward current confined chiefiy to that side of the drying chamber remote from the side Where the moisture laden atmosphere chiey descends to the condensers.

The operation of the'kiln constructed as described will be evident from the foregoing.

The material being placed in the chamber upona suitable support, as, for example, a Wheeled truck, and the door closed, the heat is applied through the steam coils or radiators, thereby heating the surrounding air and causing it to rise through the drying chamber. At the same time cold Water is introduced to the vcondensing troughs. The vapor pans or troughs having been previously filled with Water, are supplied with a small quantity'oisteam through the pipes 19, andy thewater in said troughs or vapor pans 17-18 being heated by the radiators, begins to give off a supply of vapor. There being no escape at the top of the chamber, the vapor generated in the lower part of the chamber, and that.

expelled from the commodity being treated, charges the air and causes the latter to`descend by gravity to the cooling chamberiilled with the condensing troughs, Where the air gives up its burden of vapor and again rises in its drier and rre-warmed condition. The condeiisers are kept cool by the constant flow of cold Water, which passes ofi through the drain ipe and trap.

In the modification shown in Fig. 6, means thus heated, and also additionallyA are provided for supporting the commodities to be dried at various levels Within the drying chamber, and ior supplying heatI locally at each ot these levels. To this end a series of radiator coils, severally designated 33, is provided; each coil being formed into a series of liorizontally-disposed flat loops substantially like those shown in the previous figures, and arranged to rest upon transverse supporting bars 34, vthe ends ot which are carried by channel irons or other suitable ledge members 35 secured to the side Walls of the chainber. The several radiator coils are united in series with each other to form a single closed heating system; and with the uppermost is arranged to communicate a steam -or hot- Water pipe 36; While with the lovvermost radiator coil .is connected a discharge pipe 37.

Across each ofthe coils arranged within the heating chamber proper are arranged to extend a plurality of cross bars or supports 3S, and upon these are in turn arranged supporting slats 39, upon which the commodities may rest; the arrangement being-suoli as to support' the commodities slightly above 'and out of direct contact With the radiator pipes. Of course, any suitable supporting structure for this purpose may be substituted.

The operation ol apparatus embodying this modiiication is obvious, and need not be described. It may be noted tliat in' both this modification and that previously described tlie baffle-boards not only preventthe toimation'of distinct currents of air but also serveI as shields which prevent much of the heat from the radiators reaching the condensers.

claim as my invention:

l. In a drying apparatus, the combination of a substantially closed drying chamber having insulating side and top Walls, a series of liquid troughs constitutin-g` condensers arranged in the louermost part of said chainber, a series of baffles arranged in horizontally distributed order above said condensers, a radiator coil disposed inhorizontally extended position above said baflies, one or more open water receptacles arranged in juxtaposition to said radiator coil, and means for supporting commodities in the drying chamberabovc said radiator and Water receptacle.

2. In a drying apparatus, the combination of a substantially closeddrying chamber having insulating side and top Walls, a series of liquid troughs constituting coiidensers arranged in the loivermost part of said chamber, a series of baffles arranged in horizontally distributed order above said condensers, a radiator coil disposed in horizontally extended position abovefsaid battles, one or .liveringsteam into said open .Water receptacle or receptacles, and means for supporting commodities Ain the drying chamber above said radiator and Water receptacle.

3. In a drying apparatus, the combina-- tion of a substantially closed drying chambe'r having insulating side and top' Walls, a series of open Water trou hs arranged in horizontally distributed or 'part of said chamber,` ineans aiiording a regulated supply of Water to closed radiator pipe arrangedV in horizontally .distributed-order in a zone above said condenser troughs, a series of open vapor troughs supported in proximity to saidradiator coil; means for circulating heating fluid through the radiator coil, means' for discharging steam into the contents of one or more'of said vapor troughs, and commodity supportsv arranged above the zone of the vapor troughs.

4. In a dryingapparatus, the combina? er in the lower' said troughs7` a.

'ranged 1n posed radiator pipe,4 and commodity supports ar-- erases ported proximity to said radiator coil, means for circulating heating fluid through the radiator coil, means for discharginr steam into the contents'of one or `Ymore ori said vapor troughs7 a series lof ,bafilesv ar- ,in horizontally distributed order eX- across the entire chamber and 'inter`L etWeen the condenser troughs and ten ranged above the zone of the vapor troughs.

5. In a drying apparatus, the combination of a substantially'closed chamber hav-4 ing insulating side and top wallsZ a series of condensers arranged in horizontally eX-" tended order in the bottom of said chamber,

a series of vapor generators arrangedabove 'said condensers, a series of horizontally d1s posed closed heating coils arranged at a plurality of levels throughout the drying oharnber above said vapor generatorsa heating coil arranged in proXirnity to said vapor' enerators, means forsupplying cooling uid to the oondensers, and means for circulating the heating fiuid through the several heating coils.

GERGE W. MCMULLEN.

Witnesses: J

ALBERT H. GRAVES, L. F. MCCREA. 

